Storm and Surf Microseisms 



99 



no swell at Guam. The composite graph, ignor- 

 ing distance, as well as the individual graphs 

 plotting the same values in various distance 

 categories are presented as Figure 7. 



This rather pleasing result is somewhat 

 soured by the fact that an attempt to subtract 

 the amplitude of the microseism produced by 

 the storm as shown by Figure 7 from the total 

 effect on a storm-surf microseismic record did 

 not produce any relationship between swell am- 

 plitude and microseismic activity. This may be 



the result of incorrect hypothesis, poor swell 

 forecasting or the result of the fact that the 

 microseismic amplitude as measured is not a 

 simple additive function of the two disturb- 

 ances. 



Microseismic records seem to indicate that 

 at least two phenomena are being measured 

 simultaneously. Figure 8 shows a construc- 

 tion which seems to bear this out. A simple 

 disturbance having a period of 4 units and a 

 crest-to-trough amplitude of 18 units was 



Figure 2 



